1. Field of the Invention
This invention relates to carbonylation reactions of an alcohol, ether, ester, and halide derivative thereof with carbon monoxide to form carboxylic acids and esters.
2. Description of the Prior Art
Carbonylation processes for the preparation of carboxylic acids and esters from a variety of reactants are well known in the art. One of the better known carbonylation processes involves the synthesis of acetic acid by the reaction of methanol and carbon monoxide in the presence of a catalyst. Various catalyst systems have been reported as being effective for carbonylation processes, but each has had certain disadvantages, for example, instability of the catalyst, lack of product selectivity, low levels of catalyst reactivity, or loss of highly volatile catalyst from the reaction. Particular processes are shown in the following United States patents.
U.S. Pat. No. 3,530,168 shows a process for forming carboxylic acid esters by contacting an olefin, carbon monoxide and oxygen with a catalyst comprising a Group VIII noble metal, e.g. palladium complexed with a biphyllic phosphine or arsine ligand, i.e. those having an element with a pair of electrons capable of forming a coordinate bond with a metal atom and simultaneously having the ability to accept electrons from the metal of the catalyst.
U.S. Pat. Nos. 3,769,324 and 3,772,380 disclose processes for preparing aromatic and aliphatic carboxylic acids and esters by reacting an aromatic alcohol, ester, ether and halide derivative thereof with carbon monoxide in the presence of a catalyst consisting essentially of an iridium component and a halogen component. Monodentate phosphine and arsine ligands are the only ligands shown.
U.S. Pat. No. 3,887,595 discloses a process for carbonylating olefinic unsaturated hydrocarbons to form acids, esters and acid anhydrides by catalyzing the reaction with a zero valent palladium or platinum complex stabilized with a phosphine ligand.
U.S. Pat. No. 3,917,670 discloses a process for the carbonylation of organomercurials to form carboxylic acids. In that carbonylation process, a catalyst comprising palladium complexed with a phosphine ligand is employed.
U.S. Pat. No. 3,917,677 discloses a process for preparing carboxylic acid esters by reacting an ethylenically unsaturated compound, e.g. propylene, with carbon monoxide and an alcohol in the presence of a catalyst consisting essentially of a rhodium component and a tertiary organophosphorous compound free of halogen.
U.S. Pat. No. 3,852,346 discloses a process for preparing carboxylic acid anhydrides by reacting an olefin with carbon monoxide in the presence of a rhodium or iridium compound, an iodide component and regenerator.
U.S. Pat. No. 3,923,880 discloses a process for carbonylating alcohol and alcohol derivatives to form carboxylic acids using a catalyst complex containing cations of rhodium or iridium and an anionic moiety other than halide, e.g. tetraaryl borate, phosphate, sulphate, perchlorates, iodates and bromates.